Franz Heikertinger’s rejection of natural selection

Franz Heikertinger (7.VI.1876 Wien – 24.X.1953), an Austrian entomologist. A corresponding member of many scientific societies, secretary of the Zoological and botanical society Wien and the chairman of the Department of Entomology (Sektion für Entomologie), editor of the “Koleopterologische Rundschau”. His extensive work regarding systematics and mimicry are listed on more than eight pages (1). Franz Heikertinger strongly rejected “natural selection” as the explanation of the evolution of mimicry. His discussions with “selectionists” can be found in many journals that are available on-line nowadays (2).

It is almost impossible to summarize Heikertinger’s work about mimicry in such a limited place. Yet I will try to outline his main ideas regarding the non-effectiveness of mimicry.

Franz Heikertinger rejected protective value of aposematic models. It is believed that unpalatable species signal their unpalatability by warning coloration – so called aposematism (conspicuous coloration of many insects like wasps etc. Heikertinger used the term “Schrecktracht”) . Many palatable species are believed to mimic those unpalatable species (models) and by doing so they should be protected against predators as well. Heikertinger often performed his own researches regarding aposematism and obtained results contradicting to supposed protective effect of aposematism. “Poisonous” or “unpalatable” conspicuous insects were eaten as readily as any other insect species (and without any harm – for instance eating unpalatable aposematic ladybirds (3)).

Heikertinger asked: How aposematism of ladybirds gets along with the variety of their patterns (3)?

Heikertinger also quoted many contradictory field researches which had brought up evidence that many butterflies species which were believed to be unpalatable models (in mimicry) were actually palatable. Consequently mimics of such butterflies could not obtain any protection by mimicry. Many of those examples can be found in his book “The puzzle of mimicry and its solution” (1954) which summarizes his opinions and researches (4).

Heikertinger also criticized artificial researches done on birds and insects in cages that should prove “unpalatability” of some species. He claimed that birds which are held in cages are under stress and in utterly unnatural conditions. Consequently experiments done under such circumstances have no relevance to the real feeding behaviour and often contradict what is observed in nature. The only reliable researches are those that analyze birds’ stomachs or birds pellets. He made reference to the research on Nearctic birds that had been done by the United States Biological Survey and which had taken 45 years. Stomachs of 80.000 birds had been dissected and 237.399 food items had been identified. Ornitologist McAtee summarized these results in his treatise “The Effectiveness in the Nature of the So-Called Protective Adaptations…” (1932) and concluded that protective adaptations have little or no effectiveness (5). Heikertinger also backed up the same idea by a research done by Csiki in Hungary 1905-1915 on 2.523 birds.(6)

Those ideas might be elucidated on the case of wasps and their mimics. It has been established that birds are not deterred by the sting. This interesting fact has been proved repeatedly (2004) (7). Heikertinger concluded that because of this fact there is no need to believe that wasps are protected by their taste – as “selectionists” proposed – and rejected aposematism of wasps completely. He argued that harmless wooden wasps look dangerous, but on the other hand bees as well as some African wasps look cryptic. He dismissed also so called wasp mimics. He often used systematics in doing so. For instance in this case he listed whole families and genera which members look wasps-like – be it Hymenoptera, Diptera, Lepidoptera or Coleoptera. According to his opinion yellow-black stripes are so common in the insect realm that there is no need to consider every occurence of such coloration as mimicking wasps. Otherwise there will be a mess and pure speculation which mimicry is perfect and which imperfect.(13)

Heikertinger also recommended using insect atlases in case of determination of mimicry. Often – like in the case of yellow-black stripes – the patterns are so common that mimicry is nothing else as a coincidence. On the other hand there is often a great variety of patterns in a given group. Some of those variants may look like unpalatable “models”. But Heikertinger argues that related species in a given group could look more or less similar or have the same patterns but with different colors. Because they survive as well as “mimics” there is no need to pull out any species from the sequence and present them as mimics – just because they look like another species.

Heikertinger also adressed probably the most spectacular case of polymorphic mimicry in Papilio Dardanus.

mimicry of papilio dardanus

The photo shows, on the bottom three rows, unpalatable butterfly model species in the family Danaidae (left) and palatable mimetic forms of female Papilio dardanus (right), an African swallowtail species. At top left is the Papilio dardanus male; at top right is a non-mimetic, male-like female of the same species. The polymorphic, female-limited Batesian mimicry was first described by Roland Trimen (1869). (4)

In this case some female morphs “mimic” another butterfly species, some do not mimic anything and some look like males which are nonmimetic. Three groups have been established by Frederik Nijhout (2003)(9). They have been separated into groups hippocoon, cenea and planemoides. Such a division was already done by Heikertinger 1944 (fig 28, 29, 30, 31 on the PDF page 3 or Seite 227 in the link below) (8). Heikertinger’s work hasn’t been mentioned in Frederik Nijhout paper. Yet the very interesting thing is that there exist “transitional forms” between the first and the third group. We can derive race hipopocoon gradually from Papilio dardanus tibullus via P.dardanus antinorii (Haase 1893) – P.dardanus tibullus f. trimeni (Poulton 1906) P.dardanus polytrophus f. trimeni (Eltringham 1910) to P. dardanus hippocoon (Eltrigham 1910). (fig 32-37 on the PDF page 27 orTafel 7 in the link below).(8)

Such a method elucidates Franz Heikertinger’s systematics approach to the phenomenon of mimicry. He also mentioned and discovered some beetle species that look ant-like but live in caves. So ant-like morphology has in some cases nothing to do with ant mimicry. Heikertinger also dismissed ant-like morphology and mimicry completely by claiming that ants perceive reality with antennae and we cannot judge it using our vision (which reminds us of Jakob von Uexkull’s “Umwelt”).

According to Heikertinger every insect species have its enemies and pay a tax or a toll from its ranks no matter how well it is protected by aposematism or mimicry. Because related non-mimetic forms survive as well as or even better than mimetic ones mimicry does not bestow any advantage to their bearers. In the case of Papilio Dardanus where males are non-mimetic and where non-mimetic females are sometimes more abundant than mimetic morphs in the same area auch an argument is well supported.(11)

Franz Heikertinger rejected natural selection as the source of mimetic resemblances and reduced such resemblances to pure coincidences which can be explained either by similar evolutionary sequences (chains) or by common inheritance (12). In his opinion neither aposematism nor mimicry bestow any survival advantage to their bearers.

Other intersting cases have appeared only recently. Other insects animated on wings are to be found on Macrocilix maia:

In other words there is utilization of animals of practically every kind for food approximately in proportion to their numbers. This means that predation takes place much the same as if there were no such thing as protective adaptations. And this is only another way of saying that the phenomena classed by theorists as protective adaptations have little or no effectiveness. Natural Selection theories assume discrimination in the choice of prey. The principle of proportional predation so obvious from the data contained in this paper vitiates those theories for it denotes indiscrimination, the very antithesis of selection.

“The Effectiveness in Nature of the So-Called Protective Adaptations in the Animal Kingdom, Chiefly as Illustrated by the Food Habits of Nearctic Birds.” (1932)

The evidence that birds are also deterred by the sting is very weak and unconvincing. Mostler (1935) recorded no stings suffered
by experienced adult birds, and of 70 prolonged contacts between bumblebees and young naive birds trying to eat them, there were
only three stings…

Likewise Evans & Waldbauer (1982) thought that the sting of Bombus pennsylvanicus americanorum was not the main protection
against birds. Only two of their birds were stung…

Do honeybees sting predators more or less readily than wasps ? 25-100% of toads were stung during feeding attempts (Cott, 1940;
Brower & Brower, 1965), but birds appear to be rarely if ever stung (Mostler, 1935; Liepelt, 1963), and probably the sting is
not a significant deterrent (Liepelt, 1963)…

Mostler (1935) only recorded four birds being stung by wasps in the 1082 presentations in his extensive experiments, and Liepelt
(1963) states definitively that “no wasp stings occurred” during his 99 wasp presentations, although during another series of
experiments, two Redstarts were stung…

“In Abyssinia by far the commonest female form is black and pale
yellow, nonmimetic, and looks much like the male (Plate No. 1). It accounts for 80 percent, and probably more, of the female population, and has tails, like all the other Abyssinian females. This is in contrast to the races of the “main African stock” where the females are always tailless. The next commonest form in race antinorii is niauioides (Plate No. 4), which is a modified hippocoonides, mimicking the Abyssinian form of Amauris niavius, but less well than hippocoon or hippocoonides mimic their respective local subspecies of the model. In addition there occurs in this race a much rarer butterfly, f . ruspinae, which resembles a tailed trophonius and mimics D. chrysippus. There is also a tailed cenea though this has only been reported twice, once in the south and once in the north of the region. It is a good mimic of Amauris echeria. We have also received from the Djem Djem forest a single female (unfortunately moribund) which resembled a tailed natalica, a form hitherto unreported from Abyssinia.”

“Race humbloti is restricted to the island of Grande Comore in the
volcanic Comoro Island group. It is monomorphic, the females being
tailed and resembling the males. There is much debate as to whether this race represents the primitive condition for the species (Trimen, 1869 and subsequently Poulton, 1924; Ford, 1936; Clarke & Sheppard, 1963; Turner, 1963; ‘Donald & Barrett, 1973; Clarke et al., 1985), or whether the monomorphic state is derived (van Bemmelen, 1922; Bernardi, 1963; Vane-Wright & Smith, 1991). It is interesting that two of the butterflies which act as models for the species on the mainland, Danaus chrysippus and Amauris niavius, are plentiful on the island (pers. obs.). However, it may be that the adults are not under enough predation pressure to lead to mimicry, as the bird fauna is rather restricted and their main predators are likely to be other
insects, and lizards.”

9 responses to “Franz Heikertinger’s rejection of natural selection”

What an interesting reflection! After reading The Self-Made Tapestry, by Phillip Ball, who argues for the need for biologists to take ordinary physics into account, I am very interested in a biologist’s recognition that various “adaptations” which might appear to be of competitive nature are simply present, with no good evidence that they confer a competitive advantage.

Thank you.
It was also Heikertinger’s opinion that “competition”, “selection”, “adaptation” need to be experimentally proved. His experiments, where some insects didn’t suffer any harm eating several “poisonous” bugs but died after eating fresh meat, are even amusing.